Norcold 1200 ammonia top up?

[joebedford]

We're 12 days from the end of my winter trip; then I will have all the time in the world to deal with the fridge. I'm just trying to make it last the next 12 days.

About a week ago, the fridge stopped completely freezing my ice cubes. BooHoo! A couple of pieces of meat at the bottom of the fridge went bad.

The unit is 7 years old and has performed like a champ except in 107 degree weather. It's mid-80s here and that's never been a problem before. We've been sitting in the same spot for 4 weeks now.

No error codes are displayed. Tried both electric and propane - no difference.

I'm doing the thermister test now. The fridge is cooling, just not enough.

If the ammonia system is low, would there be an error code? Can it be topped up? Just has to last 12 days.

Maybe I'll replace it with a residential fridge (though I doubt I can find one to fit past the kitchen island), but that's for doing at home, not in a campground.

[YC_1]

joebedford wrote:
I haven't seen any residue in the compartment behind the fridge or inside for that matter.

There are fans and they come on. The fridge is in a slide. I pulled the exterior covers off and can see no obstructions. There is heat coming out the top vent.

Not sure what drain hoses you mean YC 1. There is a condensate drain hose that goes into a little metal cup thingy - but only one. It looks fine.

No gurgling when it's running.

How hot should the leveling chamber be? It's warm but not too hot to touch. I guess it's the least warm part of the system right before the burner.

There may be a tee in the drain lines. It is possible they are cracked. Does the hose feel brittle?

Since you saw the fans coming on that should not be an issue.

Something has changed.

If you are running on propane the chimney might be plugged and may need a cleaning.

[joebedford]

jodeb720: not sure what baffle you mean. The only baffle I have is at the top vent. I covers all but the top 5" of the opening so that all airflow flows over the coil at the top.

Is that the one you mean or something else?

[Ivylog]

X2 on Dry Ice...many grocery stores sell it. Wrap in news paper and put in both sections if necessary. Instead of "Burping" try vibrating the bottom coils or tapping on them using a wooden dowel and a hammer. Put a fan on a ladder, if necessary, blowing into the bottom opening. Ij there is not a check valve in the end condensate line, fill the cup with water so hot air cannot back feed into the refer.

[jodeb720]

Joe,

A few years ago in my previous TT, I had a similar problem. It turns out the baffle in my dometic (I know yours is Norcold - and someone will validate this) flue rusted and parts of it fell off.

I didn't think that a baffle would make that much of a difference, but when I replaced it, the unit worked fine until I sold it 3 years later.

It could be something that simple - but you need to check to see if you have a baffle and is it intact.

Just my own experience

Josh

[pianotuna]

Joebedford,

Find a place that sells dry ice to get you home.

[joebedford]

There has been the occasional odor when opening the fridge door for a long time, but not ammonnia.

[Big_Katuna]

My 1200 died. Strong ammonia odor one day.

I went the Amish made cooling unit route. There are YouTube vids.

New unit works better than factory.

[joebedford]

I haven't seen any residue in the compartment behind the fridge or inside for that matter.

There are fans and they come on. The fridge is in a slide. I pulled the exterior covers off and can see no obstructions. There is heat coming out the top vent.

Not sure what drain hoses you mean YC 1. There is a condensate drain hose that goes into a little metal cup thingy - but only one. It looks fine.

No gurgling when it's running.

How hot should the leveling chamber be? It's warm but not too hot to touch. I guess it's the least warm part of the system right before the burner.

[YC_1]

Two things to check:
If it is mounted in a slide be sure the fans are working:

Check your drain hoses for cracks. At 7 years they are probably brittle and falling apart. Open drain hoses allow warm air inside and you will have a big problem keeping things cold in the heat.

If your drain hoses are bad try to replace them with some decent clear tubing from Lowes etc. You might have to slide the refer out to get to them but if they are bad it may be necessary.

In some cases you can find tubing that will slide over the rotten parts. Just cut those out and carefully slide some clear tubing either over or inside the old stuff. A bit of tape or silicon to make a bit of a seal might help.

When you have time be sure to replace all of the tubing.

[Old-Biscuit]

DrewE wrote:
You can't just "top off" the ammonia, no. It's actually a mixture of a few different things in the cooling unit: water, ammonia, hydrogen gas, and a corrosion inhibitor (which isn't directly involved in the cooling cycle). The whole works is under rather high pressure.

It's doubtful that just some of the refrigerant has escaped; more likely in my opinion is some other sort of problem, maybe debris blocking the ventilation airflow, or some control problem, or the door not sealing properly, or frost and ice buildup, or the cooling unit getting clogged (which isn't really repairable).

If you had an ammonia leak and were around at the time, you'd be well aware of it! You could usually also see the chromate residue left behind.

Sealed unit.....ammonia, hydrogen, sodium chromate and water under 300 psi
Sodium chromate will crystallize and plate out which can obstruct/block coolant flow causing more overheating which accumulates and slowly results in lack of cooling
(Sodium chromate is the rust inhibitor and will leave a yellowish residue when cooling unit leaks)

Norcold 1200 NEEDS external fans to more sufficient airflow across the cooling unit in order for enough heat to be removed so cooling can be accomplished.
So you have any external fans?
Are they coming on?

Items required for cooling effect
Proper heat source
Sufficient Airflow
Proper clearances/Baffles if needed
No Dead Air Spaces
Functional controls

[ctilsie242]

One way to fix it, if this is possible, is to "burp" the unit. There are better directions elsewhere, but basically one removes it, stands it upside down for 24-48 hours. Then stand it right side up for another 24 hours. Then, reinstall it. This oftentime will work for a long while.

[jerryjay11]

One tell tale sign of lost coolant in an RV fridge is a gurgling sound when it's running. Loss of ammonia may or may not be smelled as the loss of coolant will be outside of the living space. Once it has dropped to a certain level it won't necessarily have enough pressure to leak anymore.

So if you can hear a gurgling sound then it needs a new cooling unit or replacement.

I am a retired HVAC/R technician and familiar with their operation.

[MFL]

Agree with Drew, if any ammonia leaked, you'd smell it, see it, and cooling unit would be done.

Jerry

[DrewE]

You can't just "top off" the ammonia, no. It's actually a mixture of a few different things in the cooling unit: water, ammonia, hydrogen gas, and a corrosion inhibitor (which isn't directly involved in the cooling cycle). The whole works is under rather high pressure.

It's doubtful that just some of the refrigerant has escaped; more likely in my opinion is some other sort of problem, maybe debris blocking the ventilation airflow, or some control problem, or the door not sealing properly, or frost and ice buildup, or the cooling unit getting clogged (which isn't really repairable).

If you had an ammonia leak and were around at the time, you'd be well aware of it! You could usually also see the chromate residue left behind.